Brachial plexus block is a popular and widely employed regional nerve block technique for perioperative anaesthesia and analgesia for surgery of the upper extremity. The costoclavicular brachial plexus block (CCB) is a recently introduced infraclavicular approach that targets three cords located lateral to the axillary artery in the costoclavicular space .Cords in this space are located more superficially than with the classical approach at the lateral infraclavicular fossa and are clustered, while maintaining a consistent anatomical relationship with each other In addition, the costoclavicular space is considered a retrograde channel to the supraclavicular area, enabling reliable anaesthesia, including anaesthesia to the suprascapular nerve during shoulder surgery and providing additional stability in catheter placement for a continuous brachial plexus block .Because of these anatomical advantages, the CCB is emerging as a promising infraclavicular approach. Lignocaine 1% and Bupivacaine 0.5% mixture is used frequently for costoclavicular nerve block as it has early onset due to lignocaine and long duration of action due to bupivacaine from 3 to 6 h. The success of the peripheral nerve block is determined by the evaluation of sensory and motor functions. But these conventional methods (Pin-prick test and Modified Bromage Scale) are subjective, and they depend on patient’s cooperation.Many objective methods like laser doppler perfusion imager (LDPI) ,skin electrical resistance, thermographic temperature measurement have been developed to evaluate block success, these are expensive and require special devices Perfusion index (PI) is a simple, objective and noninvasive monitoring modality. It is the ratio of Pulsatile flow to Non pulsatile flow ,Pulsatile flow increases with sympathetic block in the nerve block ,hence perfusion index increases in a successful block .present study aims to evaluate the Change in perfusion index as an early objective tool to predict successful Ultrasonography guided costoclavicular block in patients posted for upper limb surgeries